220 CRUSTACEA MALACOSTRACA. III. 



The lamellae are more difficult to interpret, as I would rfbt sacrifice to some degree more than a single 

 old female and have no younger female; I suppose that the lamella marked I 2 on fig. 5 b is a reduced 

 and collapsed antenna without contents, and the lamella marked # probably the marsupial lamella be- 

 longing to first pair of legs. - - The surface of the thorax outside the ventral area described shows 

 rudiments of divisions into segments. 



Behind the thoracic part of the ventral area is found the abdominal part (fig. 5 a, ab) which is 

 a moderately chitinized plate much broader than long, and divided in almost the anterior half of its 

 median line by a cleft; this abdominal plate is not divided into segments excepting near the cleft, 

 where each narrow segment projects inwards as a process, so that the incubatory cavity is closed here 

 by these processes, which in natural position are situated as if one places the fingers of one's two hands 

 alternately between each other. 



Male. Body extremely elongate (fig. 5c). Head much produced; no eyes. -- Autenuulae (fig. 

 5 d) placed far forwards, somewhat small, but first joint extremely produced posteriorly (fig. 5 e), with 

 a number of slender and posteriorly long teeth on the major part of the inner margin, and some long 

 and slender comb-teeth on the extremely oblique posterior margin; second joint with the distal part 

 divided into some teeth; third joint with the anterior ramus short, the posterior long. Antennae nor- 

 mal, with four joints in the peduncle and five in the flagellum. - Mouth placed far backwards be- 

 tween the side-plates of first thoracic segment (fig. 5 d) ; the figure shows that mouth-parts are distinct, 

 but I do not venture an interpretation. 



Thoracic epimera in part divided by very deep incisions into several teeth (fig. 5 d). Thoracic 

 legs characteristic; the three anterior pairs (fig. 5 f ) somewhat slender, and their hand with two spines 

 at the prehensile margin; the four posterior pairs (figs. 5g and 5h) subsimilar and extremely slender, 

 with the hand (sixth joint) very long and narrow, and bearing a single minute spine a little before 

 the middle of the margin; seventh joint and claw combined as long as the hand, but seventh joint 

 thin and three to four times as long as the claw. - The five anterior abdominal segments with each 

 postero-lateral angle produced into a slender, spiniform process about two-thirds as long as the next 

 segment; pleopods with both rami movable, subsimilar in shape, very oblong, more than twice as long 

 as broad. - - Last thoracic segment, seen from above (fig. 5 i), triangular with the major part of each 

 postero-lateral margin divided into five long comb-teeth, and the pair at the median line are extremely 

 long and slender. - - Uropods with the rami very long, the exopod distinctly thinner and somewhat 

 or a little shorter than the endopod, and the ends of both rami are divided by narrow incisions 

 into comb-teeth (fig. si). 



First larval Stage (fig. sk). Body very oblong-ovate. Antennulae somewhat small, 2-jointed. 

 Antennae about as long as the thorax, 4-jointed, and the longest of its terminal setae half as long again 

 as the body. Hand of the thoracic legs oblong, with a spine at the base of the prehensile margin 

 and the "claw" short Pleopods elongate, especially their rami, and the terminal setae very long. Uro- 

 pods with the rami slender, long, and the exopod distinctly longer than the endopod; longest terminal 

 seta about as long as the body. Between the base of the uropods is seen a small, triangular process, 

 the "anal tube". 



Remarks. This genus is extremely interesting. The female, though very different from Cly- 



